The late Princess Marcella Borghese’s heirs are allegedly trying to pull a royal scam on the famed cosmetics firm she founded.

Borghese Inc. — now headed by GOP fund-raiser Georgette Mosbacher — filed a trademark-infringement suit yesterday against five members of the House of Borghese over their recent foray into sales of bath gels, pet-care products and home fragrances.

The Manhattan federal court filing says the Borgheses are illegally using the corporate name and “highly stylized crest” that Mosbacher acquired when she bought the company from Revlon.

The suit — which seeks unspecified damages — also accuses the defendants of making bogus claims tying their various businesses to their famous forebear.

Borghese Inc. says this isn’t the first time it’s had to tangle over its rights to the family’s name.

In 2006, Lorenzo Borghese was warned not to “associate himself with the Borghese brand” when he starred on the ninth season of the reality-television show “The Bachelor.”

Borghese, 38, didn’t return a message left at his company, Royal Treatment.